tests/kms_fbc_crc: fix fread() return value assertion
tests/kms_fbc_crc: fix fread() return value assertion

Use 1 as the element size to check the number of bytes returned is
greater than 0, rather than checking the number of elements returned.

This fixes a regression from commit 47f6b13 (igt.cocci: check the
return values of various functions).

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89833
Signed-off-by: Thomas Wood <b9025d6a953b68f894a0f6a80fd2af6d55b0badd@intel.com>

tiagovignatti/intel-gpu-tools,tiagovignatti/intel-gpu-tools,dlespiau/checkmate-test-igt,mv0/intel-gpu-tools,mv0/intel-gpu-tools,dlespiau/checkmate-test-igt,mv0/intel-gpu-tools,dlespiau/checkmate-test-igt,chenxianqin/intel-gpu-tools,tiagovignatti/intel-gpu-tools,tiagovignatti/intel-gpu-tools,chenxianqin/intel-gpu-tools,chenxianqin/intel-gpu-tools,mv0/intel-gpu-tools,chenxianqin/intel-gpu-tools,dlespiau/checkmate-test-igt