Under some circumstanes sendmail can loop forever collecting input.

Fix uninitialized character to prevent it.

Should go into 2.2

usr.sbin/sendmail/src/collect.c

@@ -192,6 +192,7 @@ collect(fp, smtpmode, requeueflag, hdrp, e)
 				c = *--pbp;
 			else
 			{
+				c = EOF;
 				while (!feof(fp) && !ferror(fp))
 				{
 					errno = 0;