dom0less: Remove redundant magic check in 'check_partial_fdt()'

The function 'check_partial_fdt()' performs an explicit check for the FDT
magic number (FDT_MAGIC) before calling 'fdt_check_header(). This check is
redundant, because 'fdt_check_header()' includes checking the magic number.

Remove the redundant check to simplify the code and rely on the library
function to perform header validation.

Signed-off-by: Dmytro Prokopchuk <dmytro_prokopchuk1@epam.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>

xen/common/device-tree/dom0less-build.c

@@ -359,12 +359,6 @@ static int __init check_partial_fdt(void *pfdt, size_t size)
 {
     int res;
 
-    if ( fdt_magic(pfdt) != FDT_MAGIC )
-    {
-        dprintk(XENLOG_ERR, "Partial FDT is not a valid Flat Device Tree");
-        return -EINVAL;
-    }
-
     res = fdt_check_header(pfdt);
     if ( res )
     {