Remove duplicate gcry_mac_hd_t typedef

* cipher/mac-internal.h (gcry_mac_hd_t): Remove.
--

Attempt to fix problem reported by Matthias Wachs:

 On a freebsd 9.1 amd64 and a debian Lenny x86 system:

 In file included from mac.c:27:
 mac-internal.h:22: error: redefinition of typedef 'gcry_mac_hd_t'
 ../src/gcrypt.h:1301: error: previous declaration of 'gcry_mac_hd_t' was
 here
 *** [mac.lo] Error code 1

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>
Change dummy variable in mpih-div.c to mpi_limb_t type

* mpi/mpih-div.c (_gcry_mpih_mod_1, _gcry_mpih_divmod_1): Change dummy
variable to 'mpi_limb_t' type from 'int'.
--

Patch attempts to fix problem reported by Matthias Wachs:

 while updating our buildbots I got another compile error:

 On a OS X machine:

 Darwin luke.net.in.tum.de 11.3.0 Darwin Kernel Version 11.3.0: Thu Jan
 12 18:47:41 PST 2012; root:xnu-1699.24.23~1/RELEASE_X86_64 x86_64

 /bin/sh ../libtool  --tag=CC   --mode=compile gcc -DHAVE_CONFIG_H -I.
 -I..  -I../src -I../src -I/opt/local/include -I/opt/local/include -g -O2
 -Wall -MT mpih-div.lo -MD -MP -MF .deps/mpih-div.Tpo -c -o mpih-div.lo
 mpih-div.c
 libtool: compile:  gcc -DHAVE_CONFIG_H -I. -I.. -I../src -I../src
 -I/opt/local/include -I/opt/local/include -g -O2 -Wall -MT mpih-div.lo
 -MD -MP -MF .deps/mpih-div.Tpo -c mpih-div.c  -fno-common -DPIC -o
 .libs/mpih-div.o
 mpih-div.c: In function '_gcry_mpih_mod_1':
 mpih-div.c:183: error: unsupported inline asm: input constraint with a
 matching output constraint of incompatible type!
 make[2]: *** [mpih-div.lo] Error 1
 make[1]: *** [all-recursive] Error 1
 make: *** [all] Error 2

The new x86-64 inline assembly for MPI expects outputs to be limb sized
variables (64-bit), but mpi/mpih-div.c was using 32-bit dummy variable.
Appearently this mismatch between assembly output and variable sizes does not
fail on every platform.

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>