linux: fix BR2_LINUX_KERNEL_DEFCONFIG help text

Trailing _defconfig, not leading.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
diff --git a/linux/Config.in b/linux/Config.in
index d8a5157..948d713 100644
--- a/linux/Config.in
+++ b/linux/Config.in
@@ -96,7 +96,7 @@
 	string "Defconfig name"
 	depends on BR2_LINUX_KERNEL_USE_DEFCONFIG
 	help
-	 Name of the defconfig file to use, without the leading
+	 Name of the defconfig file to use, without the trailing
 	 _defconfig
 
 config BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE