MIPS: remove broken conditional inside vpe loader code

The commit [1] breaks builds and results in the following error

	arch/mips/kernel/vpe.c: In function 'vpe_run':
	arch/mips/kernel/vpe.c:708:16: error: invalid type argument of '->' (have 'struct list_head')

Taking a closer look at the conditional we notice that list_first_entry wont
ever return NULL. The easiest fix is to just drop the dead code.

[1]
commit 3d2d0324
MIPS: vpe.c: Fix null pointer dereference in print arguments.

Signed-off-by: John Crispin <blogic@openwrt.org>