parisc: Fix compiler warnings in float emulation code

Avoid such compiler warnings:
arch/parisc/math-emu/cnv_float.h:71:27: warning: ‘<<’ in boolean context, did you mean ‘<’ ? [-Wint-in-bool-context]
     ((Dintp1(dint_valueA) << 33 - SGL_EXP_LENGTH) || Dintp2(dint_valueB))
arch/parisc/math-emu/fcnvxf.c:257:6: note: in expansion of macro ‘Dint_isinexact_to_sgl’
  if (Dint_isinexact_to_sgl(srcp1,srcp2)) {

Signed-off-by: Helge Deller <deller@gmx.de>