imply --print from --print-format

--print-format is totally useless without --print.  Implying --print
will also save us the hassle of checking it when we add transaction
option validation.

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>
Signed-off-by: Allan McRae <allan@archlinux.org>

doc/pacman.8.txt

@@ -204,7 +204,7 @@ Transaction Options (apply to '-S', '-R' and '-U')
 *\--print-format* <format>::
 	Specify a printf-like format to control the output of the '\--print'
 	operation. The possible attributes are: %n for pkgname, %v for pkgver,
-	%l for location, %r for repo, and %s for size.
+	%l for location, %r for repo, and %s for size.  Implies '\--print'.
 
 Upgrade Options (apply to '-S' and '-U')[[UO]]
 --------------------------------------------

src/pacman/pacman.c

@@ -574,6 +574,7 @@ static int parsearg_trans(int opt)
 			break;
 		case OP_PRINTFORMAT:
 			check_optarg();
+			config->print = 1;
 			config->print_format = strdup(optarg);
 			break;
 		default: