sanity: Don't use self-init for uninit()

Self-initialization like

    bool ret = ret;

is a GCC trick to suppress uninitialized variable warnings, but it's not
actually well-defined, and will trip a recent enough MemorySanitizer:

    src/eval.c:1088:13: runtime error: load of value 128, which is not a valid value for type 'bool'

3 files changed, 7 insertions, 7 deletions

diff --git a/src/eval.c b/src/eval.c
index a4c0c11..6d7afad 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -1085,7 +1085,7 @@ bool eval_or(const struct bfs_expr *expr, struct bfs_eval *state) {
  * Evaluate the comma operator.
  */
 bool eval_comma(const struct bfs_expr *expr, struct bfs_eval *state) {
-	bool ret = uninit(ret, false);
+	bool ret uninit(false);
 
 	for (struct bfs_expr *child = bfs_expr_children(expr); child; child = child->next) {
 		ret = eval_expr(child, state);
diff --git a/src/parse.c b/src/parse.c
index 3a78840..5d0f333 100644
--- a/src/parse.c
+++ b/src/parse.c
@@ -1891,11 +1891,11 @@ static int parse_mode(const struct bfs_parser *parser, const char *mode, struct
 		MODE_PLUS,
 		MODE_MINUS,
 		MODE_EQUALS,
-	} op = uninit(op, MODE_EQUALS);
+	} op uninit(MODE_EQUALS);
 
-	mode_t who = uninit(who, 0);
-	mode_t file_change = uninit(file_change, 0);
-	mode_t dir_change = uninit(dir_change, 0);
+	mode_t who uninit(0);
+	mode_t file_change uninit(0);
+	mode_t dir_change uninit(0);
 
 	const char *i = mode;
 	while (true) {
diff --git a/src/sanity.h b/src/sanity.h
index 29b3519..423e6ff 100644
--- a/src/sanity.h
+++ b/src/sanity.h
@@ -86,9 +86,9 @@
  * Initialize a variable, unless sanitizers would detect uninitialized uses.
  */
 #if SANITIZE_MEMORY
-#  define uninit(var, value) var
+#  define uninit(value)
 #else
-#  define uninit(var, value) value
+#  define uninit(value) = value
 #endif
 
 #endif // BFS_SANITY_H