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/net.c b/net.c
index d52d2e5..51a5997 100644
--- a/net.c
+++ b/net.c
@@ -1468,7 +1468,7 @@
 	const char *str = xlookup(socktypes, flags & SOCK_TYPE_MASK);
 
 	if (str) {
-		tprintf("%s", str);
+		tprints(str);
 		flags &= ~SOCK_TYPE_MASK;
 		if (!flags)
 			return;