possible typo in ancient radeon code

Hello FB devs,

This ancient code from 1da177e4c3f4: "Linux-2.6.12-rc2" from Apr 16,
2005, leads to the following static checker warning:

	drivers/video/fbdev/aty/radeon_pm.c:417 radeon_pm_enable_dynamic_mode()
	warn: we tested 'tmp & (1 << 21)' before and it was 'true'

include/video/radeon.h
  1216  #define MCLK_CNTL__MRDCKA1_SOUTSEL_MASK                 0x0c000000L
  1217  #define MCLK_CNTL__MRDCKB0_SOUTSEL_MASK                 0x30000000L
  1218  #define MCLK_CNTL__MRDCKB1_SOUTSEL_MASK                 0xc0000000L
  1219  #define MCLK_CNTL__R300_DISABLE_MC_MCLKA                (1 << 21)
  1220  #define MCLK_CNTL__R300_DISABLE_MC_MCLKB                (1 << 21)

These are probably supposed to refer to different bits.

  1221  
  1222  // MCLK_MISC

drivers/video/fbdev/aty/radeon_pm.c
   411                  /* Some releases of vbios have set DISABLE_MC_MCLKA
   412                   * and DISABLE_MC_MCLKB bits in the vbios table.  Setting these
   413                   * bits will cause H/W hang when reading video memory with dynamic
   414                   * clocking enabled.
   415                   */
   416                  if ((tmp & MCLK_CNTL__R300_DISABLE_MC_MCLKA) &&
   417                      (tmp & MCLK_CNTL__R300_DISABLE_MC_MCLKB)) {

The duplicate check here causes a warning.  I guess it probably doesn't
matter if no one complains...

   418                          /* If both bits are set, then check the active channels */
   419                          tmp = INPLL(pllMCLK_CNTL);
   420                          if (rinfo->vram_width = 64) {
   421                              if (INREG(MEM_CNTL) & R300_MEM_USE_CD_CH_ONLY)
   422                                  tmp &= ~MCLK_CNTL__R300_DISABLE_MC_MCLKB;
   423                              else
   424                                  tmp &= ~MCLK_CNTL__R300_DISABLE_MC_MCLKA;
   425                          } else {
   426                              tmp &= ~(MCLK_CNTL__R300_DISABLE_MC_MCLKA |
   427                                       MCLK_CNTL__R300_DISABLE_MC_MCLKB);
   428                          }
   429                  }


regards,
dan carpenter