Fix gdb/spu-tdep.c build breakage

Commit de63c46 ("Fix regresssion(internal-error) printing
subprogram argument (PR gdb/22670)") missed updating spu-tdep.c for
the block_lookup_symbol interface change, resulting in:

  ../../binutils-gdb/gdb/spu-tdep.c: In function void spu_catch_start(objfile*):
  ../../binutils-gdb/gdb/spu-tdep.c:1969:59: error: cannot convert domain_enum_tag to symbol_name_match_type for argument 3 to symbol* block_lookup_symbol(const block*, const char*, symbol_name_match_type, domain_enum)
	 sym = block_lookup_symbol (block, "main", VAR_DOMAIN);
							     ^

gdb/ChangeLog:
2018-01-05  Pedro Alves  <palves@redhat.com>

	* spu-tdep.c (spu_catch_start): Pass
	symbol_name_match_type::SEARCH_NAME to block_lookup_symbol.

Author: palves

gdb/ChangeLog

@@ -1,3 +1,8 @@
+2018-01-05  Pedro Alves  <palves@redhat.com>
+
+	* spu-tdep.c (spu_catch_start): Pass
+	symbol_name_match_type::SEARCH_NAME to block_lookup_symbol.
+
 2018-01-05  Pedro Alves  <palves@redhat.com>
 
 	PR gdb/22670

gdb/spu-tdep.c

@@ -1966,7 +1966,9 @@ spu_catch_start (struct objfile *objfile)
       struct symbol *sym;
       struct symtab_and_line sal;
 
-      sym = block_lookup_symbol (block, "main", VAR_DOMAIN);
+      sym = block_lookup_symbol (block, "main",
+				 symbol_name_match_type::SEARCH_NAME,
+				 VAR_DOMAIN);
       if (sym)
 	{
 	  fixup_symbol_section (sym, objfile);