analysis/latency_analysis: fix parsing for systrace
analysis/latency_analysis: fix parsing for systrace

Systrace generates formatted sched_switch events, where the prev_state
is alrady translated from integer value to its symbolic representation.

This updates the task states resolution function to fit formatted traces
as well.

Signed-off-by: Patrick Bellasi <431c86f368affbc3148c4669fbd465131f7e82cb@arm.com>

arnoldlu/lisa,ARM-software/lisa,bjackman/lisa,ARM-software/lisa,credp/lisa,ARM-software/lisa,joelagnel/lisa,credp/lisa,arnoldlu/lisa,bjackman/lisa,credp/lisa,mdigiorgio/lisa,credp/lisa,ARM-software/lisa,mdigiorgio/lisa,joelagnel/lisa