arm64: kexec_file: print appropriate variable

arm64: kexec_file: print appropriate variable

The value of kbuf->memsz may be different than kbuf->bufsz after calling
kexec_add_buffer(). Hence both values should be logged.

Fixes: 52b2a8af74360 ("arm64: kexec_file: load initrd and device-tree")
Fixes: 3751e728cef29 ("arm64: kexec_file: add crash dump support")
Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: James Morse <james.morse@arm.com>
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Link: https://lore.kernel.org/r/20200430163142.27282-2-l.stelmach@samsung.com
Signed-off-by: Will Deacon <will@kernel.org>