powerpc/pseries/mce: Improve array initialization.

This is a follow up to the patch that fixed misleading print for TLB
mutlihit due to wrongly populated mc_err_types[] array. Convert all the
static array initialization to '[x] = val' style for better
readability of array indexing and avoid any further confusion.

Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>