crypto: aesni - fix crypto_fpu_exit() section mismatch

The '__init aesni_init()' function calls the '__exit crypto_fpu_exit()'
function directly.  Since they are in different sections, this generates
a warning.

  make CONFIG_DEBUG_SECTION_MISMATCH=y
  ...
  WARNING: arch/x86/crypto/aesni-intel.o(.init.text+0x12b): Section
  mismatch in reference from the function init_module() to the function
  .exit.text:crypto_fpu_exit()
  The function __init init_module() references
  a function __exit crypto_fpu_exit().
  This is often seen when error handling in the init function
  uses functionality in the exit path.
  The fix is often to remove the __exit annotation of
  crypto_fpu_exit() so it may be used outside an exit section.

Fix the warning by removing the __exit annotation.

Signed-off-by: Jeremiah Mahler <jmmahler@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>