sh: Remove _dl_skip_args usage

Since ad43cac44a the generic code already shuffles the argv/envp/auxv
on the stack to remove the ld.so own arguments and thus _dl_skip_args
is always 0.   So there is no need to adjust the argc or argv.

Checked with qemu-user that arguments are correctly passed on both
constructors and main program.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

sysdeps/sh/dl-machine.h

@@ -149,20 +149,8 @@ _dl_start_user:\n\
 	 add r0,r12\n\
 	.align 2\n\
 1:	.long _GLOBAL_OFFSET_TABLE_\n\
-2:	! See if we were run as a command with the executable file\n\
+2:	! Get the original argument count.\n\
-	! name as an extra leading argument.\n\
-	mov.l .L_dl_skip_args,r0\n\
-	mov.l @(r0,r12),r0\n\
-	mov.l @r0,r0\n\
-	! Get the original argument count.\n\
 	mov.l @r15,r5\n\
-	! Subtract _dl_skip_args from it.\n\
-	sub r0,r5\n\
-	! Adjust the stack pointer to skip _dl_skip_args words.\n\
-	shll2 r0\n\
-	add r0,r15\n\
-	! Store back the modified argument count.\n\
-	mov.l r5,@r15\n\
 	! Compute argv address and envp.\n\
 	mov r15,r6\n\
 	add #4,r6\n\
@@ -188,8 +176,6 @@ _dl_start_user:\n\
 	.align 2\n\
 .L_dl_start:\n\
 	.long _dl_start@PLT\n\
-.L_dl_skip_args:\n\
-	.long _dl_skip_args@GOT\n\
 .L_dl_init:\n\
 	.long _dl_init@PLT\n\
 .L_dl_loaded:\n\