Stop using a large static buffer in getfdpath

   text	   data	    bss	    dec	    hex	filename
 245075	    680	   9836	 255591	  3e667	strace_old
 245143	    680	   5708	 251531	  3d68b	strace

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/defs.h b/defs.h
index ca5d088..c20fcc6 100644
--- a/defs.h
+++ b/defs.h
@@ -605,7 +605,7 @@
 extern int is_restart_error(struct tcb *);
 extern void pathtrace_select(const char *);
 extern int pathtrace_match(struct tcb *);
-extern const char *getfdpath(struct tcb *, int);
+extern int getfdpath(struct tcb *, int, char *, unsigned);
 
 extern const char *xlookup(const struct xlat *, int);