introduce bb_putchar(). saves ~1800 on uclibc (less on glibc).

diff --git a/networking/wget.c b/networking/wget.c
index 86d6f00..df1a45b 100644
--- a/networking/wget.c
+++ b/networking/wget.c
@@ -142,7 +142,7 @@
 		/* last call to progressmeter */
 		alarm(0);
 		transferred = 0;
-		putc('\n', stderr);
+		fputc('\n', stderr);
 	} else {
 		if (flag == -1) {
 			/* first call to progressmeter */