perf tests: Avoid fork in perf_has_symbol test

perf test -vv Symbols is used to indentify symbols within the perf
binary. Add the -F flag so that the test command doesn't fork the test
before running. This removes a little overhead.
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@arm.com>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: llvm@lists.linux.dev
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240221034155.1500118-4-irogers@google.com

tools/perf/tests/shell/lib/perf_has_symbol.sh

@@ -3,7 +3,7 @@
 
 perf_has_symbol()
 {
-	if perf test -vv "Symbols" 2>&1 | grep "[[:space:]]$1$"; then
+	if perf test -vv -F "Symbols" 2>&1 | grep "[[:space:]]$1$"; then
 		echo "perf does have symbol '$1'"
 		return 0
 	fi