MIPS: kdump: Set correct value to kexec_indirection_page variable

Since there is not indirection page in crash type, so the vaule of the head
field of kimage structure is not equal to the address of indirection page but
IND_DONE. so we have to set kexec_indirection_page variable to the address of
the head field of image structure.

[ralf@linux-mips.org: Don't add pointless empty line, fix trailing
whitespace damage.]

Signed-off-by: Yang Wei <Wei.Yang@windriver.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7499/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>