Bug 1218949

Building grub2 with GCC 14 discovered several incorrect mallocs (using sizeof pointer, instead of the struct):
https://build.opensuse.org/package/live_build_log/devel:gcc:next:testing/grub2/devel_gcc_next_openSUSE_Tumbleweed/x86_64

[   73s] In file included from ../grub-core/osdep/ofpath.c:2:
[   73s] ../grub-core/osdep/linux/ofpath.c: In function 'of_find_fc_host':
[   73s] ../grub-core/osdep/linux/ofpath.c:427:22: error: allocation of insufficient size '8' for type 'struct ofpath_files_list_root' with size '16' [-Werror=alloc-size]
[   73s]   427 |   portnames_file_list=malloc(sizeof(portnames_file_list));
[   73s]       |                      ^
[   73s] ../grub-core/osdep/linux/ofpath.c: In function 'of_path_of_nvme':
[   73s] ../grub-core/osdep/linux/ofpath.c:589:21: error: allocation of insufficient size '8' for type 'struct ofpath_nvmeof_info' with size '32' [-Werror=alloc-size]
[   73s]   589 |         nvmeof_info = malloc(sizeof(nvmeof_info));
[   73s]       |                     ^
[   73s] ../grub-core/osdep/linux/ofpath.c:618:21: error: allocation of insufficient size '8' for type 'struct ofpath_nvmeof_info' with size '32' [-Werror=alloc-size]
[   73s]   618 |         nvmeof_info = malloc(sizeof(nvmeof_info));
[   73s]       |                     ^

All these mallocs come from:
0002-ieee1275-ofpath-enable-NVMeoF-logical-device-transla.patch

Fix should be simple:
-        nvmeof_info = malloc(sizeof(nvmeof_info));
+        nvmeof_info = malloc(sizeof(*nvmeof_info));