arm64/EFI: minor corrections

- don't bail when using the last slot of bootinfo.mem.bank[] (due to
  premature incrementing of the array index)
- GUIDs should be static const (and placed into .init.* whenever
  possible)
- PrintErrMsg() issues a CR/LF pair itself - no need to explicitly
  append one to the message passed to the function

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/arch/arm/efi/efi-boot.h
+++ b/xen/arch/arm/efi/efi-boot.h
@@ -104,7 +104,7 @@ static int __init fdt_set_reg(void *fdt,
 
 static void __init *lookup_fdt_config_table(EFI_SYSTEM_TABLE *sys_table)
 {
-    const EFI_GUID fdt_guid = DEVICE_TREE_GUID;
+    static const EFI_GUID __initconst fdt_guid = DEVICE_TREE_GUID;
     EFI_CONFIGURATION_TABLE *tables;
     void *fdt = NULL;
     int i;
@@ -135,15 +135,15 @@ static EFI_STATUS __init efi_process_mem
              || desc_ptr->Type == EfiBootServicesCode
              || desc_ptr->Type == EfiBootServicesData )
         {
-            bootinfo.mem.bank[i].start = desc_ptr->PhysicalStart;
-            bootinfo.mem.bank[i].size = desc_ptr->NumberOfPages * EFI_PAGE_SIZE;
-            if ( ++i >= NR_MEM_BANKS )
+            if ( i >= NR_MEM_BANKS )
             {
-                PrintStr(L"Warning: All ");
-                DisplayUint(NR_MEM_BANKS, -1);
-                PrintStr(L" bootinfo mem banks exhausted.\r\n");
+                PrintStr(L"Warning: All " __stringify(NR_MEM_BANKS)
+                          " bootinfo mem banks exhausted.\r\n");
                 break;
             }
+            bootinfo.mem.bank[i].start = desc_ptr->PhysicalStart;
+            bootinfo.mem.bank[i].size = desc_ptr->NumberOfPages * EFI_PAGE_SIZE;
+            ++i;
         }
         desc_ptr = NextMemoryDescriptor(desc_ptr, desc_size);
     }
@@ -334,7 +334,7 @@ static void __init efi_arch_process_memo
     status = fdt_add_uefi_nodes(SystemTable, fdt, map, map_size, desc_size,
                                 desc_ver);
     if ( EFI_ERROR(status) )
-        PrintErrMesg(L"Updating FDT failed\r\n", status);
+        PrintErrMesg(L"Updating FDT failed", status);
 }
 
 static void __init efi_arch_pre_exit_boot(void)
@@ -408,7 +408,7 @@ static void __init efi_arch_handle_cmdli
 
     status = efi_bs->AllocatePool(EfiBootServicesData, EFI_PAGE_SIZE, (void **)&buf);
     if ( EFI_ERROR(status) )
-        PrintErrMesg(L"Unable to allocate string buffer\r\n", status);
+        PrintErrMesg(L"Unable to allocate string buffer", status);
 
     if ( image_name )
     {