[PATCH v2] libtracefs: Fix sometimes uninitialized warning.

[Ian Rogers <irogers@google.com>]

The warning with clang looks like:

src/tracefs-sqlhist.c:1107:2: error: variable 'cmp' is used uninitialized whenever switch default is taken [-Werror,-Wsometimes-uninitialized]
        default:
        ^~~~~~~
third_party/libtracefs/src/tracefs-sqlhist.c:1112:35: note: uninitialized use occurs here
                            filter->lval->field.field, cmp, val);
                                                       ^~~
third_party/libtracefs/src/tracefs-sqlhist.c:1033:2: note: variable 'cmp' is declared here
        enum tracefs_compare cmp;

Signed-off-by: Ian Rogers <irogers@google.com>
---
 src/tracefs-sqlhist.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/tracefs-sqlhist.c b/src/tracefs-sqlhist.c
index 88e9675..d77ce86 100644
--- a/src/tracefs-sqlhist.c
+++ b/src/tracefs-sqlhist.c
@@ -1097,7 +1097,8 @@ static int build_filter(struct tep_handle *tep, struct sqlhist_bison *sb,
 	case FILTER_BIN_AND:	cmp = TRACEFS_COMPARE_AND; break;
 	case FILTER_STR_CMP:	cmp = TRACEFS_COMPARE_RE; break;
 	default:
-		break;
+		fprintf(stderr, "Error invalid filter type '%d'", filter->type);
+		return ERANGE;
 	}
 
 	ret = append_filter(synth, TRACEFS_FILTER_COMPARE,
-- 
2.33.0.153.gba50c8fa24-goog