*: use "can't" instead of "cannot"

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/networking/udhcp/options.c b/networking/udhcp/options.c
index 38f9919..10ec459 100644
--- a/networking/udhcp/options.c
+++ b/networking/udhcp/options.c
@@ -255,6 +255,6 @@
 		}
 	}
 
-	bb_error_msg("cannot add option 0x%02x", code);
+	bb_error_msg("can't add option 0x%02x", code);
 	return 0;
 }