Consolidate rename Linux implementation

This patch consolidates the Linux rename implementation on
sysdeps/unix/sysv/linux/rename.c.  Current code try to use
__NR_rename if is defined and apply the same strategy for
__NR_renameat and __NR_renameat2.

Check on x86_64 and aarch64.

	* sysdeps/unix/sysv/linux/rename.c: New file.
	* sysdeps/unix/sysv/linux/generic/rename.c: Remove file.