'simple' error message functions by Loic Grenie <loic.grenie@gmail.com>.
263 bytes saved.

diff --git a/coreutils/wc.c b/coreutils/wc.c
index e86b7d4..c8a4865 100644
--- a/coreutils/wc.c
+++ b/coreutils/wc.c
@@ -150,7 +150,7 @@
 				}
 			} else if (c == EOF) {
 				if (ferror(fp)) {
-					bb_perror_msg("%s", arg);
+					bb_simple_perror_msg(arg);
 					status = EXIT_FAILURE;
 				}
 				--counts[WC_CHARS];