kconfig: Fix variable name typo %prompts in streamline_config.pl

When I added "use strict;" to streamline_config.pl, I saw the following
warnings:

> Global symbol "%prompt" requires explicit package name at
scripts/kconfig/streamline_config.pl line 183.
> Global symbol "%prompt" requires explicit package name at
scripts/kconfig/streamline_config.pl line 368.

The declaration of %prompt was incorrect, and should have been %prompts.

Cc: Toralf Foerster <toralf.foerster@gmx.de>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Hiromu Yakura <hiromu1996@gmail.com>
LKML-Reference: <1281845597.11566.5.camel@camp10-laptop>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

scripts/kconfig/streamline_config.pl

@@ -188,7 +188,7 @@ sub read_kconfig {
 	# configs without prompts must be selected
 	} elsif ($state ne "NONE" && /^\s*tristate\s\S/) {
 	    # note if the config has a prompt
-	    $prompt{$config} = 1;
+	    $prompts{$config} = 1;
 
 	# Check for if statements
 	} elsif (/^if\s+(.*\S)\s*$/) {
@@ -373,7 +373,7 @@ while ($repeat) {
 	    parse_config_dep_select $depends{$config};
 	}
 
-	if (defined($prompt{$config}) || !defined($selects{$config})) {
+	if (defined($prompts{$config}) || !defined($selects{$config})) {
 	    next;
 	}