OGL: Correctly guard against array bounds of s_encodingPrograms

s_encodingPrograms is defined as an array with a length of 64
NUM_ENCODING_PROGRAMS is also defined as 64.

However 64 is out of bounds, so we want to be comparing for "equal to or
greater than here"
Merge pull request #618 from lioncash/array-bounds

OGL: Correctly guard against array bounds of s_encodingPrograms