fbdev/hyperv_fb: Fix logic error for Gen2 VMs in hvfb_getmem()

fbdev/hyperv_fb: Fix logic error for Gen2 VMs in hvfb_getmem()

A recent commit removing the use of screen_info introduced a logic
error. The error causes hvfb_getmem() to always return -ENOMEM
for Generation 2 VMs. As a result, the Hyper-V frame buffer
device fails to initialize. The error was introduced by removing
an "else if" clause, leaving Gen2 VMs to always take the -ENOMEM
error path.

Fix the problem by removing the error path "else" clause. Gen 2
VMs now always proceed through the MMIO memory allocation code,
but with "base" and "size" defaulting to 0.

Fixes: 0aa0838c84da ("fbdev/hyperv_fb: Remove firmware framebuffers with aperture helpers")
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Link: https://lore.kernel.org/r/20240201060022.233666-1-mhklinux@outlook.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20240201060022.233666-1-mhklinux@outlook.com>