Tweak to make troff compile silently.
diff --git a/src/cmd/troff/n5.c b/src/cmd/troff/n5.c
index ab5ef2e..2c7d328 100644
--- a/src/cmd/troff/n5.c
+++ b/src/cmd/troff/n5.c
@@ -409,7 +409,7 @@
 		return;
 	}
 	if (fcache[i].fp == NULL) {
-		if( (fcache[i].fp = fopen(nextf, "w")) == NULL) {
+		if( (fcache[i].fp = fopen(unsharp(nextf), "w")) == NULL) {
 			ERROR "fm: cannot open %s", nextf WARN;
 			return;
 		}