llvm-cov: Follow LLVM naming conventions

This renames a few things that are using an unusual naming convention.

llvm-svn: 220929
diff --git a/llvm/tools/llvm-cov/gcov.cpp b/llvm/tools/llvm-cov/gcov.cpp
index bd493d2..4c9195a 100644
--- a/llvm/tools/llvm-cov/gcov.cpp
+++ b/llvm/tools/llvm-cov/gcov.cpp
@@ -84,7 +84,7 @@
   FI.print(SourceFile, GCNO, GCDA);
 }
 
-int gcov_main(int argc, const char **argv) {
+int gcovMain(int argc, const char *argv[]) {
   // Print a stack trace if we signal out.
   sys::PrintStackTraceOnErrorSignal();
   PrettyStackTraceProgram X(argc, argv);