Turn printxval macro into a static inline function

This is necessary for the upcoming change of xlat.val type.

* defs.h (printxval): Change to static inline function.
diff --git a/defs.h b/defs.h
index ef579eb..583f715 100644
--- a/defs.h
+++ b/defs.h
@@ -551,7 +551,6 @@
 extern void printaddr(long);
 extern void printxvals(const unsigned int, const char *, const struct xlat *, ...)
 	ATTRIBUTE_SENTINEL;
-#define printxval(xlat, val, dflt) printxvals(val, dflt, xlat, NULL)
 extern int printargs(struct tcb *);
 extern int printargs_u(struct tcb *);
 extern int printargs_d(struct tcb *);
@@ -667,6 +666,12 @@
 extern void unwind_capture_stacktrace(struct tcb* tcp);
 #endif
 
+static inline void
+printxval(const struct xlat *x, const unsigned int val, const char *dflt)
+{
+	printxvals(val, dflt, x, NULL);
+}
+
 /* Strace log generation machinery.
  *
  * printing_tcp: tcb which has incomplete line being printed right now.