[scudo] Add 'inline' to static secondary.h function

[Caslyn]

Summary

This patches an error flaged by Fuchsia builds when trying to roll https://reviews.llvm.org/D150481 e.g.
https://ci.chromium.org/ui/p/turquoise/builders/global.try/core.x64-asan/b8779376650819379137/overview)

../../third_party/scudo/src/secondary.h:67:13: error: 'static' function 'unmap' declared in header file should be declared 'static inline' [-Werror,-Wunneeded-internal-declaration]
static void unmap(LargeBlock::Header *H) {
            ^
1 error generated.

[Caslyn]

Provide full error message in comment

compiler-rt/lib/scudo/standalone/secondary.h

 }
 
 template <typename Config> static Header *getHeader(const void *Ptr) {
   return getHeader<Config>(reinterpret_cast<uptr>(Ptr));
 }
 
 } // namespace LargeBlock
 
-static void unmap(LargeBlock::Header *H) {
+static inline void unmap(LargeBlock::Header *H) {
   // Note that the `H->MapMap` is stored on the pages managed by itself. Take
   // over the ownership before unmap() so that any operation along with unmap()
   // won't touch inaccessible pages.
   MemMapT MemMap = H->MemMap;
   MemMap.unmap(MemMap.getBase(), MemMap.getCapacity());
 }
 
 template <typename Config> class MapAllocatorNoCache {