[Sanitizer] Bump soft_rss_limit_mb in test (llvm#170911)

This test is failing on some buildbots now that the internal shell has
been turned on and was failing previously on some ppc bots when turning
it on a while back (before it got reverted).

At least one X86 bot is barely hitting the limit
(https://lab.llvm.org/buildbot/#/builders/174/builds/28487 224MB-235MB).

This likely needs to be bumped due to changes in the process tree (now
that we invoke things through python rather than a bash shell) with the
enablement of the internal shell.

Author: boomanaiden154

compiler-rt/test/sanitizer_common/TestCases/Linux/soft_rss_limit_mb_test.cpp

@@ -2,12 +2,12 @@
 // RUN: %clangxx -O2 %s -o %t
 //
 // Run with limit should fail:
-// RUN: %env_tool_opts=soft_rss_limit_mb=220:quarantine_size=1:allocator_may_return_null=1     %run %t 2>&1 | FileCheck %s -check-prefix=CHECK_MAY_RETURN_1
-// RUN: %env_tool_opts=soft_rss_limit_mb=220:quarantine_size=1:allocator_may_return_null=0 not %run %t 2>&1 | FileCheck %s -check-prefix=CHECK_MAY_RETURN_0 --implicit-check-not="returned null"
+// RUN: %env_tool_opts=soft_rss_limit_mb=250:quarantine_size=1:allocator_may_return_null=1     %run %t 2>&1 | FileCheck %s -check-prefix=CHECK_MAY_RETURN_1
+// RUN: %env_tool_opts=soft_rss_limit_mb=250:quarantine_size=1:allocator_may_return_null=0 not %run %t 2>&1 | FileCheck %s -check-prefix=CHECK_MAY_RETURN_0 --implicit-check-not="returned null"
 
 // This run uses getrusage. We can only test getrusage when allocator_may_return_null=0
 // because getrusage gives us max-rss, not current-rss.
-// RUN: %env_tool_opts=soft_rss_limit_mb=220:quarantine_size=1:allocator_may_return_null=0:can_use_proc_maps_statm=0 not %run %t 2>&1 | FileCheck %s -check-prefix=CHECK_MAY_RETURN_0 --implicit-check-not="returned null"
+// RUN: %env_tool_opts=soft_rss_limit_mb=250:quarantine_size=1:allocator_may_return_null=0:can_use_proc_maps_statm=0 not %run %t 2>&1 | FileCheck %s -check-prefix=CHECK_MAY_RETURN_0 --implicit-check-not="returned null"
 // REQUIRES: stable-runtime
 
 // Ubsan does not intercept pthread_create.