tools/nolibc: crt.h: initialize stack protector

As suggested by Thomas, It is able to move the stackprotector
initialization from the assembly _start to the beginning of the new
_start_c(). Let's call __stack_chk_init() in _start_c() as a
preparation.
Suggested-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/lkml/a00284a6-54b1-498c-92aa-44997fa78403@t-8ch.de/Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>

tools/include/nolibc/crt.h

@@ -10,6 +10,7 @@
 char **environ __attribute__((weak));
 const unsigned long *_auxv __attribute__((weak));
 
+void __stack_chk_init(void);
 static void exit(int);
 
 void _start_c(long *sp)
@@ -21,6 +22,9 @@ void _start_c(long *sp)
 	/* silence potential warning: conflicting types for 'main' */
 	int _nolibc_main(int, char **, char **) __asm__ ("main");
 
+	/* initialize stack protector */
+	__stack_chk_init();
+
 	/*
 	 * sp  :    argc          <-- argument count, required by main()
 	 * argv:    argv[0]       <-- argument vector, required by main()