[analyzer] fix an error finding clang path

[honggyu.kim]

Summary

This patch fixes an error made by rL247466.
It mistakenly wrote "-d" check in if statement for file names.

[honggyu.kim]

After applying rL247466, I got the following error which was not shown before.

scan-build: error: Cannot find an executable 'clang' relative to scan-build.  Consider using --use-analyzer to pick a version of 'clang' to use for static analysis.

Please have a look at it.

[krememek]

Applied in r247510.

[ayartsev]

Thanks, Honggyu!

[honggyu.kim]

In D12827#244906, @ayartsev wrote:

Thanks, Honggyu!

You're welcome, Антон!

tools/scan-build/scan-build

 
 if (!@ARGV and !$RequestDisplayHelp) {
   ErrorDiag("No build command specified.\n\n");
   $ForceDisplayHelp = 1;
 }
 
 # Find 'clang'
 if (!defined $Options{AnalyzerDiscoveryMethod}) {
-  $Clang = Cwd::realpath("$RealBin/bin/clang") if (-d "$RealBin/bin/clang");
+  $Clang = Cwd::realpath("$RealBin/bin/clang") if (-f "$RealBin/bin/clang");
   if (!defined $Clang || ! -x $Clang) {
-    $Clang = Cwd::realpath("$RealBin/clang") if (-d "$RealBin/clang");
+    $Clang = Cwd::realpath("$RealBin/clang") if (-f "$RealBin/clang");
   }
   if (!defined $Clang || ! -x $Clang) {
     if (!$RequestDisplayHelp && !$ForceDisplayHelp) {
       DieDiag("error: Cannot find an executable 'clang' relative to scan-build." .
                  "  Consider using --use-analyzer to pick a version of 'clang' to use for static analysis.\n");
     }
   }
 }