Rename __JCR_LIST__ to __JCR_END__ in crtend.c.

This is more consistent with the names used for .ctor and .dtor
symbols and better reflects __JCR_END__'s role.

Reviewed by:	andrew
Obtained from:	CheriBSD
MFC after:	2 weeks
Sponsored by:	DARPA
Differential Revision:	https://reviews.freebsd.org/D27125

lib/csu/common/crtend.c

@@ -28,7 +28,7 @@ __FBSDID("$FreeBSD$");
 
 typedef void (*crt_func)(void);
 
-static crt_func __JCR_LIST__[] __section(".jcr") __used = {
+static crt_func __JCR_END__[] __section(".jcr") __used = {
 	(crt_func)0
 };