Don't require "Bss=" in qOffsets response

The "Bss=" part of the qOffsets response is documented as being
optional, but gdb in fact requires it.  This patch fixes the bug.

I couldn't find a straightforward way to test this.  gdbserver does
send 'Bss=' -- but this code is only enabled for a fairly specific
setup:

    #if (defined(__UCLIBC__)		\
	 && defined(HAS_NOMMU)		\
	 && defined(PT_TEXT_ADDR)		\
	 && defined(PT_DATA_ADDR)		\
	 && defined(PT_TEXT_END_ADDR))
    #define SUPPORTS_READ_OFFSETS
    #endif

I also considered changing gdbserver to not send Bss=, but decided
against this, reasoning that we may as well not break compatibility
with older versions of gdb.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=33319
Approved-By: Simon Marchi <simon.marchi@efficios.com>

gdb/remote.c

@@ -4669,8 +4669,6 @@ remote_target::get_offsets ()
 	  if (bss_addr != data_addr)
 	    warning (_("Target reported unsupported offsets: %s"), buf);
 	}
-      else
-	lose = 1;
     }
   else if (startswith (ptr, "TextSeg="))
     {