fio: re-enable on uClibc

The fio package was disabled on uClibc because posix_madvise() was
back then not implemented in an official release of uClibc. It now
exists in uClibc-ng since its version 1.0.0, so we can assume it's
available. We already make lots of assumptions about external uClibc
toolchains, and they should definitely be using a recent version of
uClibc-ng to be usable by Buildroot.

Also, the Config.in comment was not handling this uClibc exception.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/fio/Config.in

@@ -4,12 +4,6 @@ config BR2_PACKAGE_FIO
 	depends on !BR2_STATIC_LIBS
 	depends on BR2_TOOLCHAIN_HAS_SYNC_4
 	depends on BR2_TOOLCHAIN_HAS_THREADS
-	# fio uses posix_madvise(), which is not part of any official
-	# release of uClibc, but is part of uClibc Git, and backported
-	# in Buildroot patch set of uClibc 0.9.33. Therefore, we
-	# disable the build of fio for external uClibc toolchains
-	# (which use an unknown uClibc version)
-	depends on !BR2_TOOLCHAIN_EXTERNAL_UCLIBC
 	# fio uses fallocate() which becomes fallocate64() while compiling with
 	# largefile support, but fallocate64() is not available on nios2
 	depends on !BR2_nios2