Static analysis results

[Alexander Monakov <amonakov@ispras.ru>]

New round of static analysis results.  This time it's mostly opportunities for
very minor cleanups (I'm showing only a few results that I think make sense).
If there's a problem in balance of usefulness vs annoyance, please let me know.

dynlink.c:343
  'if (runtime)' is already established as true at line 337

sem_open.c:sem_open
  I didn't try to follow the code in detail, but it seems possible that 'goto
  fail' can be executed from e.g. line 133 after successful mmap, in which
  case the region is not unmapped

duplocale.c:17
  neither of the conditions cannot hold

dynlink.c:1503
  the first two conditions cannot hold after check at line 1489 and exit at
  line 1501

fcntl.c:42
  F_SETLKW is already taken care of at line 16
  also, why does this file cast arg to 'void *' in several places?

regcomp.c:2848
  condition 'stack != NULL' cannot hold

dynlink.c:428
  on 64-bit arches, multiplication can overflow in 32-bit type before assignment 

Alexander