Fix possible uninitialized variable insert due to previous commit.

Pointy hat to: me and my absence of -Wall in my CFLAGS.

MFC will happen at the same time of the earlier commit.

Thanks to ru@ for spotting.

Approved by:	re (Ken Smith), grog@ (mentor)

gnu/usr.bin/man/man/man.c

@@ -898,7 +898,7 @@ ultimate_source (name, path)
 #endif
 
 #if HAVE_LIBZ > 0
-  gzgets (fp, buf, BUFSIZ);
+  end = gzgets (fp, buf, BUFSIZ);
   gzclose(fp);
 #else
   end = fgets (buf, BUFSIZ, fp);