cfi: fix more -Wformat warnings

[dim]

Summary

Building cfi with recent clang on a 64-bit system results in the
following warnings:

compiler-rt/lib/cfi/cfi.cpp:233:64: warning: format specifies type 'void *' but the argument has type '__sanitizer::uptr' (aka 'unsigned long') [-Wformat]
    VReport(1, "Can not handle: symtab > strtab (%p > %zx)\n", symtab, strtab);
                                                 ~~            ^~~~~~
                                                 %lu
compiler-rt/lib/sanitizer_common/sanitizer_common.h:231:46: note: expanded from macro 'VReport'
    if ((uptr)Verbosity() >= (level)) Report(__VA_ARGS__); \
                                             ^~~~~~~~~~~
compiler-rt/lib/cfi/cfi.cpp:253:59: warning: format specifies type 'void *' but the argument has type '__sanitizer::uptr' (aka 'unsigned long') [-Wformat]
    VReport(1, "Can not handle: symtab %p, strtab %zx\n", symtab, strtab);
                                       ~~                 ^~~~~~
                                       %lu
compiler-rt/lib/sanitizer_common/sanitizer_common.h:231:46: note: expanded from macro 'VReport'
    if ((uptr)Verbosity() >= (level)) Report(__VA_ARGS__); \
                                             ^~~~~~~~~~~

Since __sanitizer::uptr has the same size as size_t, consistently
use %z as a printf specifier.

compiler-rt/lib/cfi/cfi.cpp

if (p->d_tag == DT_SYMTAB)
       symtab = p->d_un.d_ptr;
     else if (p->d_tag == DT_STRTAB)
       strtab = p->d_un.d_ptr;
     else if (p->d_tag == DT_STRSZ)
       strsz = p->d_un.d_ptr;
   }
 
   if (symtab > strtab) {
-    VReport(1, "Can not handle: symtab > strtab (%p > %zx)\n", symtab, strtab);
+    VReport(1, "Can not handle: symtab > strtab (%zx > %zx)\n", symtab, strtab);
     return 0;
   }
 
   // Verify that strtab and symtab are inside of the same LOAD segment.
   // This excludes VDSO, which has (very high) bogus strtab and symtab pointers.
   int phdr_idx;
   for (phdr_idx = 0; phdr_idx < info->dlpi_phnum; phdr_idx++) {
     const Elf_Phdr *phdr = &info->dlpi_phdr[phdr_idx];
     if (phdr->p_type == PT_LOAD) {
       uptr beg = info->dlpi_addr + phdr->p_vaddr;
       uptr end = beg + phdr->p_memsz;
       if (strtab >= beg && strtab + strsz < end && symtab >= beg &&
           symtab < end)
         break;
     }
   }
   if (phdr_idx == info->dlpi_phnum) {
     // Nope, either different segments or just bogus pointers.
     // Can not handle this.
-    VReport(1, "Can not handle: symtab %p, strtab %zx\n", symtab, strtab);
+    VReport(1, "Can not handle: symtab %zx, strtab %zx\n", symtab, strtab);
     return 0;
   }
 
   for (const Elf_Sym *p = (const Elf_Sym *)symtab; (Elf_Addr)p < strtab;
        ++p) {
     // There is no reliable way to find the end of the symbol table. In
     // lld-produces files, there are other sections between symtab and strtab.
     // Stop looking when the symbol name is not inside strtab.