nir: remove duplicated foreach loop

The foreach loop was called both in the else case and right after. The
indentation seems to indicate that the extra call was from a previous
version with an else section with out curly brackets.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>

src/compiler/nir/nir_from_ssa.c

@@ -970,7 +970,6 @@ nir_lower_ssa_defs_to_regs_block(nir_block *block)
       } else {
          nir_foreach_dest(instr, dest_replace_ssa_with_reg, &state);
       }
-         nir_foreach_dest(instr, dest_replace_ssa_with_reg, &state);
    }
 
    return state.progress;