gas/riscv: Fix grammar in error messages

gas/config/tc-riscv.c

diff --git a/gas/config/tc-riscv.c b/gas/config/tc-riscv.c
index 5f7683e..f1a48bf 100644
--- a/gas/config/tc-riscv.c
+++ b/gas/config/tc-riscv.c
@@ -5848,7 +5848,7 @@
       if (!start_assemble)
 	riscv_set_arch (attr[Tag_RISCV_arch].s);
       else
-	as_fatal (_("architecture elf attributes must set before "
+	as_fatal (_("architecture elf attributes must be set before "
 		    "any instructions"));
 
       if (old_xlen != xlen)
@@ -5866,7 +5866,7 @@
     case Tag_RISCV_priv_spec_minor:
     case Tag_RISCV_priv_spec_revision:
       if (start_assemble)
-       as_fatal (_("privileged elf attributes must set before "
+       as_fatal (_("privileged elf attributes must be set before "
 		   "any instructions"));
       break;