wrappers: fix guard in clang-hash-stop

wrappers/clang-hash-stop.in

@@ -3,7 +3,7 @@
 # Wrapper for clang, that supports (only) fast hash-based
 # recompilation.
 
-if [[ ( "$@" =~ ".* -c .*") && ( "$@" =~ ".* -o. *" ) && ! ( "$@" =~ ".*/dev/null" ) ]]; then
+if [[ ( "$@" =~ .*" -c".* ) && ( "$@" =~ .*" -o".* ) && ! ( "$@" =~ .*"/dev/null".* ) ]]; then
     exec ${LLVM_C_COMPILER} -fplugin=${PROJECT_BINARY_DIR}/src/libclang-hash.so \
          -Xclang -plugin-arg-clang-hash -Xclang -stop-if-same-hash \
          "$@"