[committed] gdb/csky fix build error in ubuntu20_04

[Jiangshuai Li <jiangshuai_li@linux.alibaba.com>]

build error in: https://builder.sourceware.org/buildbot/#/builders/170/builds/246
...
../../binutils-gdb/gdb/csky-linux-tdep.c: In function ‘void
csky_supply_fregset(const regset*, regcache*, int, const void*, size_t)’:
../../binutils-gdb/gdb/csky-linux-tdep.c:194:18: error: format ‘%ld’
expects argument of type ‘long int’, but argument 2 has type ‘size_t’
{aka ‘unsigned int’} [-Werror=format=]
   194 |       warning (_("Unknow size %ld of section .reg2, can not get
value"
       |
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   195 |    " of float registers."), len);
...

Fix it via using %s vs pulongest suggested by Tom.
---
 gdb/csky-linux-tdep.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/gdb/csky-linux-tdep.c b/gdb/csky-linux-tdep.c
index 106f629b8b0..ae5d2bba33c 100644
--- a/gdb/csky-linux-tdep.c
+++ b/gdb/csky-linux-tdep.c
@@ -191,8 +191,8 @@ csky_supply_fregset (const struct regset *regset,
     }
   else
     {
-      warning (_("Unknow size %ld of section .reg2, can not get value"
-		 " of float registers."), len);
+      warning (_("Unknow size %s of section .reg2, can not get value"
+		 " of float registers."), pulongest (len));
     }
 }
 
@@ -272,8 +272,8 @@ csky_collect_fregset (const struct regset *regset,
     }
   else
     {
-      warning (_("Unknow size %ld of section .reg2, will not set value"
-		 " of float registers."), len);
+      warning (_("Unknow size %s of section .reg2, will not set value"
+		 " of float registers."), pulongest (len));
     }
 }
 
-- 
2.25.1