avr32: fix relocation check for signed 18-bit offset
avr32: fix relocation check for signed 18-bit offset

Caught by static code analysis by David.

Reported-by: David Binderman <b6d239d25020cc5e235b79047ed71f02d7363ad6@hotmail.com>
Signed-off-by: Hans-Christian Egtvedt <11ce19a6fc3bb47abce595a29a6ea4cfed5efa4c@samfundet.no>
Cc: 4fbacc2fa0ffdbb11bf1ad6925b886ebd08dd15f@kernel.org

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas