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/signal.c b/signal.c
index 31c5a65..84af14f 100644
--- a/signal.c
+++ b/signal.c
@@ -385,13 +385,13 @@
 static void
 printsigmask(sigset_t *mask, int rt)
 {
-	tprintf("%s", sprintsigmask("", mask, rt));
+	tprints(sprintsigmask("", mask, rt));
 }
 
 void
 printsignal(int nr)
 {
-	tprintf("%s", signame(nr));
+	tprints(signame(nr));
 }
 
 void