The driver prints pcsr twice: the first time it uses specifier %px to
print hexadecimal pcsr value and the second time uses specifier %pS for
output kernel symbols.
As suggested by Kees, using %pS should be sufficient and %px isn't
necessary; the reason is if the pcsr is a kernel space address, we can
easily get to know the code line from %pS format, on the other hand, if
the pcsr value doesn't fall into kernel space range (e.g. if the CPU is
stuck in firmware), %pS also gives out pcsr hexadecimal value.
So this commit removes useless %px and update section "Output format"
in the document for alignment between the code and document.