arch: Get rid of the unused numAccessNeeded variable.

This was defined in a few operand classes makeConstructor methods, but
never used for anything.

Change-Id: If2f62ff0a29a26ae7067728651440f864999fc67
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/49718
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>

src/arch/isa_parser/operand_types.py

@@ -344,8 +344,6 @@ class VecRegOperand(Operand):
         c_src = ''
         c_dest = ''
 
-        numAccessNeeded = 1
-
         if self.is_src:
             c_src = self.src_reg_constructor % (self.reg_class, self.reg_spec)
 
@@ -474,8 +472,6 @@ class VecElemOperand(Operand):
         c_src = ''
         c_dest = ''
 
-        numAccessNeeded = 1
-
         if self.is_src:
             c_src = ('\n\tsetSrcRegIdx(_numSrcRegs++, RegId(%s, %s));' %
                     (self.reg_class, self.reg_spec))