arm64: fpsimd: fix a typo in fpsimd_save_partial_state ENDPROC

Commit 190f1ca8 ("arm64: add support for kernel mode NEON in interrupt
context") introduced a typing error in fpsimd_save_partial_state ENDPROC.

This patch fixes the typing error.

Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: byungchul.park <byungchul.park@lge.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>