We were using the effective sized internal format as the upload format
of glTexImage*() calls. This caused issues when using e.g.
GL_RGBA16F with GL_RGBA / GL_FLOAT.

Change-Id: I2dbd7142447c5330eec1895b1a9652ac20f8414a
Reviewed-on: https://swiftshader-review.googlesource.com/16448Tested-by: Nicolas Capens <nicolascapens@google.com>
Tested-by: Lingfeng Yang <lfy@google.com>
Reviewed-by: Lingfeng Yang <lfy@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>