[libFuzzer] fix missing close on opened file

Summary:
When running the standalone main on a large corpus, I eventually get a
EMFILE error ("Too many open files").

Patch by Paul Chaignon

Reviewers: kcc, vitalybuka

Reviewed By: vitalybuka

Subscribers: lebedev.ri, #sanitizers, llvm-commits

Tags: #llvm, #sanitizers

Differential Revision: https://reviews.llvm.org/D58622

llvm-svn: 354918

compiler-rt/lib/fuzzer/standalone/StandaloneFuzzTargetMain.c

@@ -32,6 +32,7 @@ int main(int argc, char **argv) {
     fseek(f, 0, SEEK_SET);
     unsigned char *buf = (unsigned char*)malloc(len);
     size_t n_read = fread(buf, 1, len, f);
+    fclose(f);
     assert(n_read == len);
     LLVMFuzzerTestOneInput(buf, len);
     free(buf);