seccomp: Use pr_fmt

Avoid open-coding "seccomp: " prefixes for pr_*() calls.
Signed-off-by: Kees Cook <keescook@chromium.org>

kernel/seccomp.c

@@ -13,6 +13,7 @@
  * Mode 2 allows user-defined system call filters in the form
  *        of Berkeley Packet Filters/Linux Socket Filters.
  */
+#define pr_fmt(fmt) "seccomp: " fmt
 
 #include <linux/refcount.h>
 #include <linux/audit.h>
@@ -1873,7 +1874,7 @@ static int __init seccomp_sysctl_init(void)
 
 	hdr = register_sysctl_paths(seccomp_sysctl_path, seccomp_sysctl_table);
 	if (!hdr)
-		pr_warn("seccomp: sysctl registration failed\n");
+		pr_warn("sysctl registration failed\n");
 	else
 		kmemleak_not_leak(hdr);