common: env: remove superfluous assignment

The value assigned to variable 'value' is never used.

The problem was indicated by clang scan-build.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/cmd/nvedit.c b/cmd/nvedit.c
index 9ca5cb5..8f4e6bb 100644
--- a/cmd/nvedit.c
+++ b/cmd/nvedit.c
@@ -234,7 +234,6 @@
 	}
 	debug("Final value for argc=%d\n", argc);
 	name = argv[1];
-	value = argv[2];
 
 	if (strchr(name, '=')) {
 		printf("## Error: illegal character '='"