Fix "format not a string literal" warning caused by tprintf(str)

* defs.h: Declare tprints().
* strace.c: Define tprints().
(tabto): Use tprints(str), since tprintf(str) was throwing a warning.
* desc.c: Use tprints(str) instead of tprintf("%s", str).
* file.c: Likewise.
* io.c: Likewise.
* net.c: Likewise.
* process.c: Likewise.
* signal.c: Likewise.
* syscall.c: Likewise.
* util.c: Likewise.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
diff --git a/syscall.c b/syscall.c
index b21ce01..02dce95 100644
--- a/syscall.c
+++ b/syscall.c
@@ -683,7 +683,7 @@
 			return 0;
 		}
 		nargs = sysent[scno].nargs;
-		tprintf("%s", sysent[scno].sys_name);
+		tprints(sysent[scno].sys_name);
 		for (i = 0; i < nargs; i++)
 			tprintf(", %#lx", tcp->u_arg[i+1]);
 	}