perf/x86: Remove unused assignment to pointer 'e'

The pointer 'e' is being assigned a value that is never read, the assignment
is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20210804115710.109608-1-colin.king@canonical.com