[AVR] Don't worry about call frame size when initializing frame pointer

We previously only used the frame pointer if the frame pointer was too
big. This was to work around a bug (described in this old commit)

https://sourceforge.net/p/avr-llvm/code/204/tree//llvm/trunk/AVR/AVRFrameLowering.cpp?diff=50d64d912718465cb887d17a:203

I mistakenly invered the condition assuming it was a typo. I am now
removing it because it doesn't seem to be a problem anymore (plus it's a
dirty hack).

llvm-svn: 283639
diff --git a/llvm/lib/Target/AVR/AVRFrameLowering.cpp b/llvm/lib/Target/AVR/AVRFrameLowering.cpp
index 342c90a..dd70078 100644
--- a/llvm/lib/Target/AVR/AVRFrameLowering.cpp
+++ b/llvm/lib/Target/AVR/AVRFrameLowering.cpp
@@ -45,10 +45,9 @@
   // conditions:
   // - Y pointer is reserved to be the frame pointer.
   // - The function does not contain variable sized objects.
-  // - MaxCallFrameSize doesn't fit into 6-bits (when it's greater than 63).
+
   const MachineFrameInfo &MFI = MF.getFrameInfo();
-  return (hasFP(MF) && !MFI.hasVarSizedObjects() &&
-          !isUInt<6>(MFI.getMaxCallFrameSize()));
+  return hasFP(MF) && !MFI.hasVarSizedObjects();
 }
 
 void AVRFrameLowering::emitPrologue(MachineFunction &MF,