Fix sparse warning: Using plain integer as NULL pointer

This patch fixes the "using plain integer as NULL pointer" warnings
generated by running sparse on the flashrom source.

Corresponding to flashrom svn r1255.

Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Acked-by: Mathias Krause <mathias.krause@secunet.com>
Acked-by: Stefan Reinauer <stepan@coreboot.org>
diff --git a/cli_classic.c b/cli_classic.c
index 1211989..88b70db 100644
--- a/cli_classic.c
+++ b/cli_classic.c
@@ -116,23 +116,23 @@
 
 	static const char optstring[] = "r:Rw:v:nVEfc:m:l:i:p:Lzh";
 	static const struct option long_options[] = {
-		{"read", 1, 0, 'r'},
-		{"write", 1, 0, 'w'},
-		{"erase", 0, 0, 'E'},
-		{"verify", 1, 0, 'v'},
-		{"noverify", 0, 0, 'n'},
-		{"chip", 1, 0, 'c'},
-		{"mainboard", 1, 0, 'm'},
-		{"verbose", 0, 0, 'V'},
-		{"force", 0, 0, 'f'},
-		{"layout", 1, 0, 'l'},
-		{"image", 1, 0, 'i'},
-		{"list-supported", 0, 0, 'L'},
-		{"list-supported-wiki", 0, 0, 'z'},
-		{"programmer", 1, 0, 'p'},
-		{"help", 0, 0, 'h'},
-		{"version", 0, 0, 'R'},
-		{0, 0, 0, 0}
+		{"read", 1, NULL, 'r'},
+		{"write", 1, NULL, 'w'},
+		{"erase", 0, NULL, 'E'},
+		{"verify", 1, NULL, 'v'},
+		{"noverify", 0, NULL, 'n'},
+		{"chip", 1, NULL, 'c'},
+		{"mainboard", 1, NULL, 'm'},
+		{"verbose", 0, NULL, 'V'},
+		{"force", 0, NULL, 'f'},
+		{"layout", 1, NULL, 'l'},
+		{"image", 1, NULL, 'i'},
+		{"list-supported", 0, NULL, 'L'},
+		{"list-supported-wiki", 0, NULL, 'z'},
+		{"programmer", 1, NULL, 'p'},
+		{"help", 0, NULL, 'h'},
+		{"version", 0, NULL, 'R'},
+		{NULL, 0, NULL, 0}
 	};
 
 	char *filename = NULL;