[libFuzzer] [NFC] Fix grammar error with "it's"

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk/lib/fuzzer@372937 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/FuzzerLoop.cpp b/FuzzerLoop.cpp
index 9c26673..7150a11 100644
--- a/FuzzerLoop.cpp
+++ b/FuzzerLoop.cpp
@@ -513,7 +513,7 @@
 }
 
 void Fuzzer::CrashOnOverwrittenData() {
-  Printf("==%d== ERROR: libFuzzer: fuzz target overwrites it's const input\n",
+  Printf("==%d== ERROR: libFuzzer: fuzz target overwrites its const input\n",
          GetPid());
   DumpCurrentUnit("crash-");
   Printf("SUMMARY: libFuzzer: out-of-memory\n");