build: suppress more warnings

* src/fid.c (usage): Declare with __noreturn__ attribute.
* src/fnid.c (usage): Likewise.
* src/lid.c (usage): Likewise.
* src/mkid.c (usage): Likewise.
* src/xtokid.c: (usage): Likewise.
* src/mkid.c (sum_files): Remove unused macro.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/lid.c b/src/lid.c
index f4e23b9..5519109 100644
--- a/src/lid.c
+++ b/src/lid.c
@@ -93,7 +93,7 @@ enum radix
   radix_all = radix_dec | radix_oct | radix_hex
 };
 
-void usage (void);
+void usage (void) __attribute__((__noreturn__));
 static void help_me (void);
 static void lower_caseify (char *str);
 static enum key_style parse_key_style (char const *arg);