PCI: Remove assignment from "if" conditions

The following Coccinelle semantic patch was used to find and correct cases
of assignments in "if" conditions:

@@
expression var, expr;
statement S;
@@

+ var = expr;
  if(
- (var = expr)
+ var
  ) S

Signed-off-by: Quentin Lambert <lambert.quentin@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>