virfile: fix cast-align error

virfile: fix cast-align error

On s390x the struct member f_type of statsfs is hard coded to 'unsigned
int'. Change virFileIsSharedFixFUSE() to take a 'long long int' and use
a temporary to avoid pointer-casting.

This fixes the following error:
../../src/util/virfile.c:3578:38: error: cast increases required alignment of target type [-Werror=cast-align]
         virFileIsSharedFixFUSE(path, (long *) &sb.f_type);

Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Bjoern Walk <bwalk@linux.ibm.com>