package/fluent-bit: fix build with BR2_TIME_BITS_64

Do not remove _FILE_OFFSET_BITS=64 from CFLAGS to avoid the following
build failure with BR2_TIME_BITS_64 raised since commit
3c427c64726560ea1743282a3fdb78f5b28692eb:

In file included from /home/thomas/autobuild/instance-1/output-1/host/microblaze-buildroot-linux-gnu/sysroot/usr/include/features.h:394,
                 from /home/thomas/autobuild/instance-1/output-1/host/microblaze-buildroot-linux-gnu/sysroot/usr/include/bits/libc-header-start.h:33,
                 from /home/thomas/autobuild/instance-1/output-1/host/microblaze-buildroot-linux-gnu/sysroot/usr/include/stdio.h:27,
                 from /home/thomas/autobuild/instance-1/output-1/build/fluent-bit-2.1.7/tools/xxd-c/xxd-c.c:27:
/home/thomas/autobuild/instance-1/output-1/host/microblaze-buildroot-linux-gnu/sysroot/usr/include/features-time64.h:26:5: error: #error "_TIME_BITS=64 is allowed only with _FILE_OFFSET_BITS=64"
   26 | #   error "_TIME_BITS=64 is allowed only with _FILE_OFFSET_BITS=64"
      |     ^~~~~

Indeed, this LFS workaround was present since the addition of the
package in commit 6a0f7c39bcb48fc13aa2ce3fc4996baf1be66483 and is
only needed to fix a build failure with the old codesourcery-arm
toolchain from 2014 which uses glibc < 2.23. as glibc 2.23 was released
in February 2016: https://sourceware.org/glibc/wiki/Release/2.23, drop
this workaround as already done for libselinux in commit
c1fa9bc2f7a4e5481edf4fce5c03dd45862fe72c. A follow-up patch will also
drop codesourcery-arm toolchain.

Fixes: 3c427c64726560ea1743282a3fdb78f5b28692eb
 - http://autobuild.buildroot.org/results/ff5c60cd038550453ce138fe2a9383af2f5d6f2f

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/fluent-bit/fluent-bit.mk

@@ -12,8 +12,6 @@ FLUENT_BIT_CPE_ID_VENDOR = treasuredata
 FLUENT_BIT_CPE_ID_PRODUCT = fluent_bit
 FLUENT_BIT_DEPENDENCIES = host-bison host-flex libyaml openssl
 
-FLUENT_BIT_CFLAGS = $(TARGET_CFLAGS)
-
 FLUENT_BIT_CONF_OPTS += \
 	-DFLB_DEBUG=No \
 	-DFLB_RELEASE=Yes \
@@ -55,11 +53,6 @@ FLUENT_BIT_CONF_OPTS += \
 FLUENT_BIT_CONF_OPTS += \
 	-DCMAKE_INSTALL_SYSCONFDIR="/etc/"
 
-# Undefining _FILE_OFFSET_BITS here because of a "bug" with glibc fts.h
-# large file support.
-# https://bugzilla.redhat.com/show_bug.cgi?id=574992
-FLUENT_BIT_CFLAGS += -U_FILE_OFFSET_BITS
-
 ifeq ($(BR2_PACKAGE_LIBEXECINFO),y)
 FLUENT_BIT_DEPENDENCIES += libexecinfo
 FLUENT_BIT_LDFLAGS += -lexecinfo
@@ -76,8 +69,7 @@ FLUENT_BIT_LDFLAGS += -latomic
 endif
 
 FLUENT_BIT_CONF_OPTS += \
-	-DCMAKE_EXE_LINKER_FLAGS="$(FLUENT_BIT_LDFLAGS)" \
-	-DCMAKE_C_FLAGS="$(FLUENT_BIT_CFLAGS)"
+	-DCMAKE_EXE_LINKER_FLAGS="$(FLUENT_BIT_LDFLAGS)"
 
 define FLUENT_BIT_INSTALL_INIT_SYSV
 	$(INSTALL) -D -m 0755 package/fluent-bit/S99fluent-bit \