target/s390x: Fix MDEB and MDEBR

target/s390x: Fix MDEB and MDEBR

These instructions multiply 32 bits by 32 bits, not 32 bits by 64 bits.

Fixes: 83b00736f3d8 ("target-s390: Convert FP MULTIPLY")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: qemu-stable@nongnu.org
Message-Id: <20230704081506.276055-4-iii@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
(cherry picked from commit fed9a4fe0ce0ec917a6b3a2da0a7ecd3cb9eba56)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>