bootconfig: Mark boot_config_checksum() static

In fact, this function is only used in this file, so mark it with 'static'.

Link: http://lkml.kernel.org/r/1581852511-14163-1-git-send-email-hqjagain@gmail.com

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

init/main.c

@@ -335,7 +335,7 @@ static char * __init xbc_make_cmdline(const char *key)
 	return new_cmdline;
 }
 
-u32 boot_config_checksum(unsigned char *p, u32 size)
+static u32 boot_config_checksum(unsigned char *p, u32 size)
 {
 	u32 ret = 0;