powerpc: Move branch instruction from ACCOUNT_CPU_USER_ENTRY to caller

[PATCH 1/6] powerpc: Move branch instruction from ACCOUNT_CPU_USER_ENTRY to caller

The first instruction in ACCOUNT_CPU_USER_ENTRY is 'beq' which checks for
exceptions coming from kernel mode. PPR value will be saved immediately after
ACCOUNT_CPU_USER_ENTRY and is also for user level exceptions. So moved this
branch instruction in the caller code.

Signed-off-by: Haren Myneni <haren@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>